Motor-starting switch



July 3, 1928. 7 1,676,077-

A. c. BUNKER MOTOR STARTING SWITCH Inventor,

B W $44 AHo'rney.

I Arthur C. Bunker;

July 3, 1928. 1,676,077

. A. c. BUNKER MOTOR STARTING swwcn Mia. '1924 2 Sheets-Sheet 2 I IFH'H Fig- 4.

Inve ntor Arthur c. B unker, By M 714444 Attorney.

Patented July 3, 1928.

'ARTHUR'Q. BUNKER, 0E MONTOLAIRyNEW JERSEY; AssIGNoa TO' CRQ EE-WHEEEER- ELECTRIC MANUTACTURINGGOMPflN-Y, OEAMPEREINEW JERSEY; A-- COREPORA- TION or" NEW-JERSEY;

or Free;

MOTOEsTARTINGJSwjI'TCEJ ,OIie object or "this invention is to provide a'switeh for electric motors which con trol heavy currelits, antlwfiill ailtolrititi'ca llyf function so that the requisite interval will ru'r'ming connections after the stertihgi of the switch movement has been" initiated. Another object is to provide it switch which can be used where dustt or inflammable ve'p'ors are present Without danger offez'qil'ofsion'; A further object is] to 7 provide a switch in which opening'and' exposure of the switch contaotsj' while current is flowing; therethro'ugh' is automatically preventedj A further object is' to rovi de' switch of compact anclrugged eo n'st ruotion. I

In the aceompanyifig two sheets of draw ings which form a part ofthisspeoificzttioli; Figure '1 is a front View of theswitchfin ofiiposition, the co ver' being removed, the tank being lowered, and the tankfahd dash-1 pot being' shown-iri'fseetiong V I Fig. 2 's a section'on theli1'1e"IIII"o'f Fi 1. 1

%ig. 3 is a rear View of thel'ma-inswitch member; v Fig. {i is a diagram of the circguits. A cas 5, wit-ha cov'erfi encloses suitable actuating mechanism. It's lower side is a slab ofinsula'ting material as wood oiflslsrte against which e'tmhk'i' for oilis held and in which the main switch contests are made and broken; The'tenk has'a lip 8 which en'gagedbythe cover of the CiiSGf fi TldI the tank is looked in place thereby. '9, 9 depend from thecase and nuts 10 10 on the lower ends of theirorls engage urflierslottecl ears 11, 11,011 thesicles of the'tnik near t'he bottom. ,The rods also p'a'ss through holes in ears 12,12 on the sidesof the tanket top. It is therefore'only necessary tore move the cover and slackenthe nuts tolslic le them out ofengagemefltwith'the slotted ears and lower the tank to the, position shown in which .oil which temporarilfad heres" to the switch parts can dra iii into the tank but to remove the tank forienip'tying and cleaning, thenuts must be removed the upper ears are not slotted as the auto-transformers, which are {used Fin starting and the motor lezicl'si.

e, The fingers areshowrr in the diagrammatic v figure in a single row for convenience in- 'illustrating the I circuits, hilt they are "prefr ably disposed intwo P opposed h orizontil rows, one behind th'eothefohfthe samelet el andthej'rearfmw including: the which are directlyconnecitedfto thelinefleatls so that when the swi teh is open all of themore aieeessible parts will be dead; The con neotiOIl S are mfzicle for stertingend ruiin-ing"by suitably interconnecting the fingers three of a main switch member the-'lowerfp'artfof whih' is theforrri of' aiwoodehboard 28.

och of the contact sec'tioiis is m1- inverted U-shep ed iece, its two branches wing 0n the two side's ofthe board and its connecting board; wooden. cztp pi ee'e 129"is screwed to the top edge of the "board which oarries the Contact" sections and the fingersbttr egairist'the two sides of this wlfefi the switch i'sjf opeir. The proper conneetiolis "are made, for stztiting and then for runnin'gjby lifting the main: switch member so as to bring first the contacts 'irijthe ugper' rowson the tw o sid'es into Contact with the fingers, and finally thec0ntacts in the lower 'rows into conta'ot with the fingers. Springs 30, 30

drop, the plain switch member to the ope'ii position shown wh re. t isnot suppqrtecl." lifting 'rocl arm matwheel "te the sweet which is actuated by a spring 45.

member and extends upwardly through the bottom of the case into the case. In the case is a solenoid 32 with an armature 33 which carries pawls 34, 34 arranged to engage with notches 35, 35 in the two edges of the lifting rod. The stroke of the solenoid armature is slightly greater than the distance which the main switch member is moved in going from the open position to the starting position or in going from the starting position to the running position. Current is supplied to the solenoid for the initial stroke in lifting the main switch member'to the starting position by closing a starting switch 36. The circuit is then from one of the line leadsthrough a lead 37 the starting switch, through a lead 38, a contact spring 39 to a pilotswitch member 40 in which the pilot switch member is connected permanently through a flexible lead 41 to the, solenoid. Thence the circuit is through a lead42 to another line lead. I

' When the main switch is lifted to the first position a pin 43 on the lifting rod is removed from engagement with a .lever 44 i This spring is not of, sui'licient strength to interfere with. the dropping of the main switch member. The lever having been released, it lifts-through a latch 46, a piston rodi47 which carries the pilot switch and also a piston 48 of adash-pot 49. The dash-pot is preferably filled with oil to a sufficient height .to cover t-hepilot switch in order to reduce the hazard in case the switch is where theatmospheremay beenplosive from the ceived current and a circuit has been established. from one of the motor-leads through a lead 52, a stopping switch 53,-a lead 54, a. no-volta-ge release magnet 55, a lead 56, a safetyv switch 57, and a lead 58 to a. terminal of .one of the auto-transformers which is con nected' to one of the line leads through the main switch. A roller 59 on an arm of the no-voltage release magnet armature engages a notch 60 on the lift rod and prevents the main switch from falling back with the armature of the solenoid.

After a sufiicient interval of time for the motor to start and speed up so that final running connections may be made, the pilot switch will near the upper limit of its travel and the circuit through the solenoid will he again established. through that portion, of the'pilot switch which is below the insulating collar. If in the meantime the op erator has opened the starting switch, there will be a second path for current through a lead 61 and a contact spring 62, so that the switch having started to close will go to full tions. It isretained in this position by the engagement of a notch 64 in the lift rod by the roller on the arm of the no-voltage release magnet armature; As the spring-actuated lever nears the upper limit of its movement the tail of the latch which is carried by it will engag'ea pin and the piston rod will be released'and will fall, but it willonly' fall part way when it will be stopped by a pin 66 carried by the piston rod striking the top of the spring actuated lever which is in the position shown in dotted lines. This shifts the pilot switch so that all connections through it are broken and the solenoid has no current while the main switch continues in the running positionand nocircuit can be made throughfthe starting switch until the main switch has gone back to its open position and the spring actuated lever has been. engaged by the pin on the lift rod and brought down to the position shown.

The mainswitch is returned to open position by opening the stopping switch which breaks the circuit through the no-voltage release magnet and lets the main switch member fall.

Should the cover to the case be removed while contacts are made, the removal of the cover will. release the safety switch and the main switch will at once dropto the open position and cannot be operated from the starting switch until the safety switch has been closed by putting back the cover. Also as it is necessary to remove the cover before thetank is released, it follows that the contacts in it cannot be'exposed while current is flowing.

I claim- 1. In a motor starting switch, means for establishing motor startingconnections, means for establishing motor running connections, an actuating magnet, a circuit therefor, a reciprocating armature therefor, means for coupling the reciprocating armature'to the means for establishing motor starting connections, a pilot switch with delayed movement for openingand reclosing the circuit for the actuating magnet after motor starting connections are established to effect a second reciprocation of the actuating magnet, and means for coupling the reciproeating armature to the means "for establishing motor running connections on the second reciprocation of the actuating magnet.

2. A motor starting switch, actuating mechanism therefor, an oil-tank in which the switch is submerged, a case for the actuating mechanism provided with a cover, means connected with the cover for locking the oiltank in position, a no-voltage release magnet for retaining the switch in actuated p0sition, and a safety switch in the circuit of the 10 no-voltage release magnet which is held closed by the cover of the case.

ARTHUR C. BUNKER. 

